Dual-fuel engine

Abstract

A cylinder cover is provided with an air inlet channel, the outer side wall of the air inlet channel is detachably and fixedly connected with a methanol fuel injector assembly, the methanol fuel injector assembly comprises a methanol fuel injector and a valve seat, and the methanol fuel injector is detachably and fixedly connected with the valve seat. An alcohol inlet pipe installation hole is formed in the side portion of the valve seat, a cylinder cover connector is arranged at the bottom of the valve seat, an installation boss is arranged on the outer side wall of the air inlet channel, a valve seat installation hole is formed in the installation boss, the cylinder cover connector is connected with the valve seat installation hole in an inserted mode, an included angle alpha is formed between the center line of the valve seat installation hole and the center line of the cylinder sleeve hole, and the included angle alpha is larger than or equal to 40 degrees and smaller than or equal to 50 degrees. According to the dual-fuel engine, the improvement cost is low, meanwhile, the replacement rate of diesel oil replaced by methanol in the dual-fuel engine is increased, and in addition, interference between the methanol fuel injector assembly and a cylinder cover of the dual-fuel engine is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of internal combustion engines, in particular to a dual-fuel engine. Background Art

[0002] As the market continues to change, the country's emission requirements for internal combustion engines are also constantly increasing. In order to adapt to this environment, dual-fuel engines have been derived. Diesel-methanol dual-fuel engines are engines that use diesel and methanol as fuel. They have diesel mode and diesel / methanol dual-fuel mode. The diesel mode is a working mode that uses diesel as fuel; the diesel / methanol dual-fuel mode is a working mode that uses diesel and methanol as dual fuels. Diesel-methanol dual-fuel engines meet the country's emission requirements.

[0003] Diesel-methanol dual-fuel engines are usually modified based on diesel engines. Since methanol is in liquid form under normal conditions, it cannot be directly burned and used. In order for diesel engines to burn methanol, methanol fuel injectors are required to spray methanol in a certain form (atomized) into the combustion chamber of the diesel engine, and ignite the methanol through pre-combustion of diesel, thereby providing kinetic energy.

[0004] In the prior art, when some diesel engines are converted into diesel-methanol dual-fuel engines, the conversion cost is high, and the substitution rate of methanol for diesel is relatively low. In addition, the existing diesel engine cylinder head has a compact structure, while the methanol injector inlet in the prior art is arranged along its axial direction, and the methanol injector is located at the top of the methanol injector. When the top methanol injector is connected to an external joint and an alcohol inlet pipeline, the axial dimension is too long. When installed on the original diesel engine cylinder head, it is easy to interfere with the exhaust pipe or water pipe on the cylinder head, resulting in the methanol injector being difficult to install or even impossible to install.

[0005] Therefore, in the process of converting the existing diesel engine into a dual-fuel engine, it is necessary to reduce. In addition, it is necessary to avoid interference between the methanol fuel injector assembly and the dual-fuel cylinder head. Utility Model Content

[0006] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the utility model is to provide a dual-fuel engine, which not only has a low modification cost, but also can improve the substitution rate of methanol for diesel in the dual-fuel engine, and in addition, can avoid interference between the methanol fuel injector assembly and the cylinder head of the dual-fuel engine.

[0007] In order to solve the above technical problems, the utility model adopts the following technical solutions:

[0008] A dual-fuel engine comprises a cylinder head, wherein the cylinder head is provided with an air intake passage, and a methanol fuel injector assembly is detachably and fixedly connected to an outer wall of the air intake passage, and is characterized in that:

[0009] The methanol fuel injector assembly comprises a methanol fuel injector and a valve seat, wherein the methanol fuel injector is detachably fixedly connected to the valve seat, a methanol inlet pipe mounting hole is provided on the side of the valve seat, and a cylinder head connector is provided at the bottom of the valve seat.

[0010] A mounting boss is provided on the outer wall of the intake passage, a valve seat mounting hole is provided at the mounting boss, the cylinder head connector is plugged into the valve seat mounting hole, an angle α is formed between the center line of the valve seat mounting hole and the center line of the cylinder liner hole, 40°≤α≤50°.

[0011] Preferably, the top surface of the mounting boss is a valve seat mounting surface, and the valve seat mounting hole is arranged perpendicular to the valve seat mounting surface.

[0012] Preferably, the distance from the center of the valve seat mounting surface to the center of the cylinder head combustion surface is H, 250mm≤H≤260mm.

[0013] Preferably, a lateral protruding joint protruding radially is provided on the side of the valve seat, the alcohol inlet pipe mounting hole is provided at the lateral protruding joint, and a double-walled methanol pipe is fixedly installed in the alcohol inlet pipe mounting hole.

[0014] Preferably: the double-walled methanol pipe is fixedly connected to the alcohol inlet pipe mounting hole via a connecting joint, the double-walled methanol pipe is plugged and fixed to the connecting joint, and the connecting joint is plugged and fixed to the alcohol inlet pipe mounting hole.

[0015] Preferably: an O-ring is installed between the double-wall methanol pipe and the connecting joint, and an O-ring is installed between the connecting joint and the mounting hole of the alcohol inlet pipe.

[0016] Preferably, an O-ring is installed between the cylinder head connector and the valve seat mounting hole.

[0017] Preferably, the methanol fuel injector is fixedly connected to the valve seat via a first screw.

[0018] Preferably, the valve seat of the methanol fuel injector assembly is fixedly connected to the mounting boss of the intake passage by a second screw.

[0019] Preferably, a valve guide is fixedly mounted on the cylinder head, and the valve can reciprocate along the valve guide to adjust the intake and exhaust volumes in the cylinder.

[0020] After adopting the above technical solution, the beneficial effects of the utility model are:

[0021] The dual-fuel engine of the utility model ensures that the original cylinder head structure remains unchanged as much as possible, and a mounting boss is set on the outer wall of the intake duct. At the same time, the methanol fuel injector is improved, mainly by adding a detachable fixed valve seat to transform it into a methanol fuel injector assembly. The methanol fuel injector assembly is fixed on the mounting boss on the outer wall of the intake duct. There is an angle α between the center line of the valve seat mounting hole and the center line of the cylinder liner hole, 40°≤α≤50°, and the angle α determines the layout position of the methanol fuel injector assembly, and then determines the direction of the methanol nozzle of the methanol fuel injector. 40°≤α≤50° ensures that the direction of the methanol nozzle of the methanol fuel injector is directly aligned with the intake valve position, ensuring that as much methanol as possible enters the combustion chamber through the methanol fuel injector. When the valve is opened, methanol enters the combustion chamber in an atomized state along with the air flow direction, so that methanol replaces part of diesel combustion to provide power. This structure can greatly improve the substitution rate of methanol for diesel, so that the dual-fuel engine not only meets the national emission regulations, but also saves the use cost for customers.

[0022] In addition, the valve seat of the methanol fuel injector is detachably fixedly connected to the methanol injector, and an alcohol inlet pipe mounting hole is provided on the side of the valve seat, and a double-walled methanol pipe is fixedly installed in the alcohol inlet pipe mounting hole, and methanol is smoothly introduced into the inlet area of ​​the methanol injector through the double-walled methanol pipe connected on the side. The top alcohol inlet method in the prior art is changed to a side alcohol inlet method. Not only does it realize the functional requirement of the methanol injector to feed methanol from the side, but the methanol fuel injector assembly also avoids interference with components such as the exhaust pipe or water pipe on the engine, is easy to install and disassemble, and reduces the overall cost of the methanol fuel injector assembly.

[0023] In summary, the dual-fuel engine of the present invention not only has a low modification cost, but also improves the substitution rate of methanol for diesel in the dual-fuel engine. In addition, interference between the methanol fuel injector assembly and the cylinder head of the dual-fuel engine is avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the methanol fuel injector assembly of the dual-fuel engine of the utility model being installed on the cylinder head;

[0025] Figure 2 yes Figure 1 Schematic diagram of the enlarged structure at Z in the middle;

[0026] Figure 3 It is a partial schematic diagram of the cylinder head;

[0027] Figure 4 is a three-dimensional structural schematic diagram of a methanol fuel injector assembly;

[0028] 1. Cylinder head; 101. Intake duct; 102. Mounting boss; 103. Cylinder liner hole; 1021. Valve seat mounting hole; 2. Methanol fuel injector assembly; 201. Methanol fuel injector; 202. Valve seat; 2020. Lateral protruding joint; 2021. Cylinder head connector; 3. Valve; 4. Combustion chamber; C. Valve seat mounting surface; E. Cylinder head combustion surface; 5. Double-wall methanol pipe; 6. Connecting joint; 7. O-ring; 8. First screw; 9. Second screw; f. Direction of methanol nozzle spraying; t. Air flow direction. DETAILED DESCRIPTION

[0029] The technical solution of the utility model is described in detail below in conjunction with the accompanying drawings and specific embodiments to further understand the purpose, solution and effect of the utility model, but it is not intended to limit the scope of protection of the claims attached to the utility model.

[0030] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0031] In addition, although the terms first, second, third, etc. can be used in the text to describe multiple elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms can only be used to distinguish an element, component, region, layer or section from another region, layer or section. Unless the context clearly indicates, terms such as "first", "second" and other numerical terms do not imply order or sequence when used in the text. Therefore, the first element, component, region, layer or section discussed below can be referred to as the second element, component, region, layer or section without departing from the teaching of the example embodiments.

[0032] like Figure 1 , Figure 2 and Figure 3 As shown, the dual-fuel engine includes a cylinder head 1, on which an intake passage 101 is provided.

[0033] A methanol fuel injector assembly 2 is detachably fixedly connected to the outer wall of the intake duct 101, and the methanol fuel injector assembly 2 includes a methanol fuel injector 201 and a valve seat 202. The methanol fuel injector 201 is detachably fixedly connected to the valve seat 202. A methanol inlet pipe mounting hole is provided on the side of the valve seat 202, and a cylinder head connector 2021 is provided at the bottom of the valve seat 202. A mounting boss 102 is provided on the outer wall of the intake duct 101, and a valve seat mounting hole 1021 is provided at the mounting boss 102. The cylinder head connector 2021 is plugged into the valve seat mounting hole 1021, and an angle α is formed between the center line of the valve seat mounting hole 1021 and the center line of the cylinder liner hole 103, and the angle is 40°≤α≤50°.

[0034] A valve guide is fixedly mounted on the cylinder head 1, and the valve 3 can reciprocate along the valve guide to adjust the intake and exhaust volume in the cylinder.

[0035] The dual-fuel engine of the present invention keeps the original cylinder head 1 structure unchanged as much as possible. Figure 2 As shown, a mounting boss 102 is provided on the outer wall of the intake passage 101. Meanwhile, the methanol fuel injector 201 is improved mainly by adding a detachable fixed valve seat 202, and is transformed into Figure 4 The methanol fuel injector assembly 2 shown. The methanol fuel injector assembly is mounted and fixed on the mounting boss 102 on the outer wall of the intake passage 101. There is an angle α between the center line of the valve seat mounting hole 1021 and the center line of the cylinder liner hole 103. The angle α determines the layout position of the methanol fuel injector assembly, and further determines the direction f of the methanol nozzle of the methanol fuel injector 201. If the angle α is not designed properly, the methanol will be sprayed onto the inner wall of the intake passage during the injection process instead of being sprayed onto the valve 3, which will lead to a low replacement rate of methanol for diesel in the dual-fuel engine, resulting in the emission of the entire diesel engine not meeting the regulations.

[0036] In the present invention, the range of the angle α is preferably set to 40°≤α≤50°, ensuring that the direction f of the methanol nozzle of the methanol fuel injector 201 is directly aimed at the position of the intake valve 3, ensuring that as much methanol as possible enters the combustion chamber 4 through the methanol fuel injector 201. When the valve 3 is opened, methanol enters the combustion chamber 4 in an atomized state along with the air flow direction t, so that methanol replaces part of the diesel combustion to provide power. This structure can greatly increase the substitution rate of methanol for diesel, so that the dual-fuel engine not only meets the national emission regulations, but also saves the use cost for customers.

[0037] The size of the valve seat mounting hole 1021 can be adjusted to accommodate the installation of methanol fuel injector assemblies of different sizes.

[0038] The dual-fuel engine of the utility model will ensure that the original cylinder head 1 structure remains unchanged as much as possible, and only the mounting boss 102 is provided on the outer side wall of the intake duct 101, so that the structural change of the mold for casting the cylinder head is small during casting, the modification is simple, the modification cost is low, and the engine has interchangeability.

[0039] In some embodiments, the top surface of the mounting boss 102 is the valve seat mounting surface C, and the valve seat mounting hole 1021 is vertically arranged to the valve seat mounting surface C.

[0040] In some embodiments, the dimension of the mounting boss 102 protruding from the outer wall of the intake passage 101 cannot be too high or too low, and the distance from the center of the valve seat mounting surface C to the center of the cylinder head combustion surface E is H, 250mm≤H≤260mm.

[0041] In some embodiments, a lateral protruding joint 2020 protruding radially is provided on the side of the valve seat 202, and an alcohol inlet pipe mounting hole is opened at the lateral protruding joint 2020, and a double-walled methanol pipe 5 is fixedly installed in the alcohol inlet pipe mounting hole.

[0042] The top methanol inlet method in the prior art is changed to a side methanol inlet method, that is, the inlet of the methanol fuel injector 2 is set at the side through the valve seat 202, and the methanol is smoothly introduced into the inlet area of ​​the methanol injector through the double-walled methanol pipe 5 connected to the side.

[0043] In some embodiments, to improve the sealing performance and prevent methanol leakage, Figure 2 As shown, the double-walled methanol pipe 5 is fixedly connected to the mounting hole of the alcohol inlet pipe through the connecting joint 6, the double-walled methanol pipe 5 is plugged and fixed to the connecting joint 6, and the connecting joint 6 is plugged and fixed to the mounting hole of the alcohol inlet pipe. An O-shaped sealing ring 7 is installed between the double-walled methanol pipe 5 and the connecting joint 6, and an O-shaped sealing ring 7 is installed between the connecting joint 6 and the mounting hole of the alcohol inlet pipe.

[0044] An O-ring 7 is installed between the cylinder head connector 2021 and the valve seat mounting hole 1021. This improves the sealing performance between the valve seat 202 and the cylinder head 1, and prevents methanol leakage at the interface between the two.

[0045] In some embodiments, to ensure sealing so that methanol fuel does not leak out, the valve seat 202 is made of austenitic stainless steel, and the sealing parts such as the O-ring 7 are made of fluororubber (with a fluorine content greater than 70%).

[0046] The above-mentioned methanol fuel injector 201 and valve seat 202 are detachably fixedly connected, which not only realizes the functional requirement of lateral methanol injection of the methanol injector, but also avoids interference between the methanol fuel injector assembly and components such as the exhaust pipe or water pipe on the engine, while facilitating installation and disassembly and reducing costs.

[0047] In some embodiments, Figure 4As shown, to facilitate installation and removal of the methanol fuel injector 201 and the valve seat 202, the methanol fuel injector 201 and the valve seat 202 are fixedly connected by a first screw 8. Preferably, a threaded hole is provided on the valve seat 202, and the first screw 8 is installed in the threaded hole.

[0048] In some embodiments, in combination Figure 2 and Figure 4 As shown, the valve seat 202 of the methanol fuel injector assembly 2 is fixedly connected to the mounting boss 102 of the intake passage 101 by the second screw 9. Corresponding screw mounting holes are provided on the valve seat 202 and the mounting boss 102, and the second screw 9 is installed at the screw mounting hole to fix the valve seat 202 and the mounting boss 102. In this embodiment, the methanol fuel injector assembly 2 is fixed to the cylinder head 1 by three second screws 9, and the connection is reliable and easy to disassemble and assemble.

[0049] In summary, the dual-fuel engine of the present invention not only has a low modification cost, but also improves the substitution rate of methanol for diesel in the dual-fuel engine. In addition, interference between the methanol fuel injector assembly and the cylinder head of the dual-fuel engine is avoided.

[0050] The present invention is not limited to the above embodiments, and all improvements based on the concept, principle, structure and method of the present invention are within the protection scope of the present invention.

Claims

1. A dual-fuel engine, comprising a cylinder head, wherein the cylinder head is provided with an air intake passage, and a methanol fuel injector assembly is detachably fixedly connected to the outer wall of the air intake passage, characterized in that: The methanol fuel injector assembly comprises a methanol fuel injector and a valve seat, wherein the methanol fuel injector is detachably fixedly connected to the valve seat, a methanol inlet pipe mounting hole is provided on the side of the valve seat, and a cylinder head connector is provided at the bottom of the valve seat. A mounting boss is provided on the outer wall of the intake passage, a valve seat mounting hole is provided at the mounting boss, the cylinder head connector is plugged into the valve seat mounting hole, an angle α is formed between the center line of the valve seat mounting hole and the center line of the cylinder liner hole, 40°≤α≤50°.

2. The dual fuel engine according to claim 1, characterized in that: The top surface of the mounting boss is a valve seat mounting surface, and the valve seat mounting hole is arranged perpendicular to the valve seat mounting surface.

3. The dual fuel engine according to claim 1, characterized in that: The distance from the center of the valve seat mounting surface to the center of the cylinder head combustion surface is H, 250mm≤H≤260mm.

4. The dual fuel engine according to claim 1, characterized in that: A lateral protruding joint protruding radially is provided on the side of the valve seat, and the alcohol inlet pipe mounting hole is provided at the lateral protruding joint, and a double-wall methanol pipe is fixedly mounted on the alcohol inlet pipe mounting hole.

5. The dual fuel engine according to claim 4, characterized in that: The double-walled methanol pipe is fixedly connected to the alcohol inlet pipe mounting hole via a connecting joint, the double-walled methanol pipe is plugged and fixed to the connecting joint, and the connecting joint is plugged and fixed to the alcohol inlet pipe mounting hole.

6. The dual fuel engine according to claim 5, characterized in that: An O-ring is installed between the double-wall methanol pipe and the connecting joint, and an O-ring is installed between the connecting joint and the mounting hole of the methanol inlet pipe.

7. The dual fuel engine according to claim 1, characterized in that: An O-ring is installed between the cylinder head connector and the valve seat mounting hole.

8. The dual fuel engine according to claim 1, characterized in that: The methanol fuel injector is fixedly connected to the valve seat via a first screw.

9. The dual fuel engine according to claim 1, characterized in that: The valve seat of the methanol fuel injector assembly is fixedly connected to the mounting boss of the intake passage by a second screw.

10. The dual fuel engine according to claim 1, characterized in that: A valve guide is fixedly mounted on the cylinder head, and the valve can reciprocate along the valve guide to adjust the intake and exhaust volume in the cylinder.

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